Light weight ribbed composite armor

ABSTRACT

A combination of a steel ribbed plate bolted to an aluminum tank shell, wherein the ribbed plate is made up of a series of short vertical or inclined high hardness plates welded to a lower hardness steel plate wherein the initial ribbed plates break up the incoming projectile and the aluminum tank shell absorbs the fragmented projectile.

United States Patent [191 Pagano et al.

[ 1 Oct. 16, 1973 LIGHT WEIGHT RIBBED COMPOSITE ARMOR [75] Inventors: Victor H. Pagano, Rochester; Harry Spiro, Detroit, both of Mich.

[73] Assignee: The United States of America as represented by the Secretary of the Army, Washington, DC.

[22] Filed: June 9, 1968 [21] Appl. No.: 697,565

[52] US. Cl. 89/36 H [51] Int. Cl. F4lh 7/04 [58] Field of Search 89/36 R, 36 A, 36 H; 109/49.5, 78, 80, 82, 83, 84, 85

[56] References Cited UNITED STATES PATENTS 532,857 1/1895 Appelt 109/82 X 2,102,963 12/1937 Miller 109/78 UX 2,318,301 5/1943 Eger 89/36 A UX 3,351,374 11/1967 Forsyth et a1. 89/36 T UX FOREIGN PATENTS OR APPLICATIONS 1,103,549

OTHER PUBLICATIONS Johnston, Robert L., Air Armament, ORDNANCE, Nov.-Dec. 1967, Vol. LII, No. 285, p. 220.

Primary ExaminerStephen C. Bentley Attorney-Harry M. Saragovitz, Edward J. Kelly, Herbert Berl and Maxwell V. Wallace [57] ABSTRACT A combination of a steel ribbed plate bolted to an aluminum tank shell, wherein the ribbed plate is made up of a series of short vertical or inclined high hardness plates welded to a lower hardness steel plate wherein the initial ribbed plates break up the incoming projectile and the aluminum tank shell absorbs the fragmented projectile.

7 Claims, 5 Drawing Figures 5/1955 France 89/36 A PATFNTEDUCI 16|975 INVENTORS, Victor H. Pagano Harry \Sp'nro ATTORNEYS LIGHT WEIGHT RIBBED COMPOSITE ARMOR This invention described herein may be manufactured, used and licensed by or for the Government for governmental purposes without payment to us for any royalty thereon.

This invention relates to armor and more particularly to a new and improved type of armor that will provide homogeneous steel and aluminum armor for light weight vehicles.

It has been found that armor used on vehicles today weighs too much. The very low weight development armors are either too costly, lack complete ballistic armor integrity, multiple hit capability, or restrict vehicle usable space. It has been discovered that a combination of a steel ribbed plate bolted to an aluminum plate, wherein the ribbed plate is made up of a series of short'vertical or inclined high hardness plates (500 BI-IN) welded to a lower hardness steel plate (300 BI-IN), produces a new and unique result.

The aluminum plate simulates the basic structure of a vehicle with major emphasis on light weight and structure rigidity. With this design it hasv been found that the short high hardness plates or ribs break up the incoming projectile and the aluminum back-up plate absorbs the fragmented projectile. Also with the present design it has been found that by altering the mass energy distribution and absorbing the energy with the more efficient fragment resisting materials anew and improved armor is provided. The hard steel ribs and their orientation to an oncoming projectile provides the best arrangement for assuring projectile shattering. The projectile plate interaction does two things. First, the kinetic energy of the projectile is reduced by initial impact with the ribs and the accompanying shattering of the projectile. Second, the projectile mass becomes more dispersed resulting in a lower penetrating energy per square inch of surface area. Since the high hardness steel ribs cannot be welded directly to the aluminum armor, they are welded to a steel plate. This plate in turn can be mounted onto an aluminum vehicle, or the like, by plug welding, rivets or bolts.

The principal object of the present invention is to provide a new and improved light weight ribbed armor that will provide the maximum damage to a projectile on impact.

Another object of the invention is to provide a new and improved armor having formed integrally thereon ribbed design configurations to inflict maximum damage to a projectile on impact.

A still further object of the invention is to provide a new and improved armor having incorporated therein a light metal backup plate to provide an optimum base for fabricating rigid structures.

Another object of the invention is to provide a new and improved armor having ribbed design configuration formed thereon and having a plastic fill therebetween to act as a plug against moisture and to improve vehicle bouyancy.

The above and other objects of the invention will appear more fully from the following more detailed description and from the drawing, wherein:

FIG. 1, is a side elevational view showing the ribbed armor secured to a tank in panel form.

FIG. 2, is a front view of one of the panels with the ribs on a 30 angle slanting downwardly.

FIG. 3, is a front view of one of the panels with the ribs extending horizontally from the plate.

FIG. 4, is a cross section of FIG. 3; and

FIG. 5, is a section taken substantially along line 5-5 of FIG. 2.

Referring now to the drawing, the numeral l0 designates a conventional tank showing the exterior ribs 12 on armor plate M, the ribs being formed as shown best in FIGS. t and 5, the same being approximately 1 inch in length and one quarter inch thick either in panel form, or running the entire side of the vehicle on a single plate, much in the fashion of a venitian blind with the leading edge of each rib turned downwardly. Each rib is approximately three quarters of an inch from the center of one rib to another and set on the steel side armor at a 30 angle, or parallel to each other as shown in FIG. 4.

The ribbed plate is made up of a series of short vertical or inclined high hardness plates (500 BHN), which in turn are welded to a lower hardness steel plate 14, (300 BI-IN). The plate 14 is bolted to an aluminum vehicle 16 by means of bolts 13.

The manner in which the armor operates is as follows:

With the type of armor herein disclosed the tank hull may be constructed of aluminum, titanium, ceramic, etc., to provide the lightest possible base armor.

The combined outer or auxiliary armor comprising the ribbed armor 12 secured to the backup plate 14 is secured to the tank hull by means of bolts lid, the auxiliary armor being formed in large sheets or in panel form and applied to the base of the tank hull as described. The rib members 12 run the entire length of the side of the tank in aligned panels and protrude therefrom approximately 1 inch and are approximately one quarter inch in thickness and they are superimposed one above the other approximately three quarters of an inch from center to center and are pitched at approximately 30, as shown in FIGS. 2 and 5. As shown, the longitudinal ribs are pitched downwardly, but may be pitched upwardly if desired. Also, as shown in FIG. 4, the ribs 12 may protrude parallel to each other equi-distant apart.

A plastic fill, not shown, may be applied between the rib members 112, such as polyurethane fire-retardent foam fill, to act as a water repellent to aid buoyancy and to prevent corrosion.

The ribbed armor is also mounted on the front and rear of the vehicle in the same manner as described for the mounting of the side armor.

When a round is fired at a vehicle armored as set forth herein, the short high hardness plates or ribs break up the incoming projectile while the aluminum backup plate absorbs the fragmented projectile. The hard steel ribs and their orientation to the oncoming projectile represents the best known means for assuring projectile shattering. The kinetic energy of the projectile is reduced by initial impact with the ribs and the accompanying shattering of the projectile. Also the projectile mass becomes more dispersed resulting in a lower penetrating energy per square inch of surface area.

Since the high hardness steel ribs cannot be welded directly to the aluminum armor, they are welded to a steel plate and the plate is mounted upon the aluminum vehicle hull by plug welding, rivets, bolts, or even explosive bonding.

The ribbed steel plate is designed in such a way that it will inflict the maximum damage to the projectile on impact. The second material, aluminum, or the like, is softer and offers greater thickness for its weight, high section modulus, and thereby provides a large capacity for absorbing energy. This is particularly true where the source of energy is from a multi-particle dispersed mass.

There has been disclosed herein a unique type of armor which in turn combines a number of ballistic principles observed between projectiles and various targets, i.e., mechanics of projectile breakup against spaced targets, influence of hardness on projectile shattering, etc., into a light weight configuration of two armor materials. The first material is designed to inflict the maximum damage to a projectile on impact, while the second softer material offers greater thickness for its weight and provides a larger capacity for absorbing energy which is particularly true where the source of energy is from a multi-particle dispersed mass. The ribbed design configuration used in the front plate, which is of high hardness, and light metal backup plate and the overall dissimilar metal combination make for a greater advance in the armor art. The aluminum backup plate also provides an optimum base for fabricating rigid structures which is idea] because it places no reliance on the steel for needed structural durability and thus simplifies the fabrication problem permitting use of dissimilar material combination.

We wish it to be understood that we do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

We claim:

1. Armor means for fragmentizing a projectile comprising,

a steel ribbed plate member,

said plate member being secured flush against an aluminum plate member,

said ribbed steel plate member being capable of fragmentizing said projectile, and

said aluminum plate member being capable of absorbing said fragmented projectile.

2. An armor means as set forth in claim 1, wherein,

said means for fragmentizing said projectile comprises,

a plate whereon said ribs protrude obliquely therefrom.

3. An armor means as set forth in claim 2, wherein,

said ribs extend at an angle of 60 from said plate.

4. An armor means as set forth in claim 1, wherein,

said means for fragmentizing said projectile comprises,

a plate member having mounted thereon a plurality of superimposed rib members,

said rib members having greater tensil strength than said plate member.

5. In combination, a tank having an outer shell formed of aluminum, to which is secured a plurality of steel ribbed panel members,

said ribbed steel panel members providing means for fragmentizing a projectile, and

wherein said aluminum tank shell is capable of and provides means for absorbing said fragmented projectile.

6. The combination of claim 4, wherein,

said ribbed steel panel members extend groundward at an acute angle from the horizontal.

7. The combination of claim 5 wherein said acute angle is 30. 

1. Armor means for fragmentizing a projectile comprising, a steel ribbed plate member, said plate member being secured flush against an aluminum plate member, said ribbed steel plate member being capable of fragmentizing said projectile, and said aluminum plate member being capable of absorbing said fragmented projectile.
 2. An armor means as set forth in claim 1, wherein, said means for fragmentizing said projectile comprises, a plate whereon said ribs protrude obliquely therefrom.
 3. An armor means as set forth in claim 2, wherein, said ribs extend at an angle of 60* from said plate.
 4. An armor means as set forth in claim 1, wherein, said means for fragmentizing said projectile comprises, a plate member having mounted thereon a plurality of superimposed rib members, said rib members having greater tensil strength than said plate member.
 5. In combination, a tank having an outer shell formed of aluminum, to which is secured a plurality of steel ribbed panel members, said ribbed steel panel members providing means for fragmentizing a projectile, and wherein said aluminum tank shell is capable of and provides means for absorbing said fragmented projectile.
 6. The combination of claim 4, wherein, said ribbed steel panel members extend groundward at an acute angle from the horizontal.
 7. The combination of claim 5 wherein said acute angle is 30*. 